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/****************************************************************************
* arch/arm/src/armv7-a/arm_va2pte.c
* Utility to map a virtual address to a L2 page table entry.
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <debug.h>
#include <nuttx/sched.h>
#include <nuttx/page.h>
#include "chip.h"
#include "pg_macros.h"
#include "up_internal.h"
#ifdef CONFIG_PAGING
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: arm_va2pte
*
* Description:
* Convert a virtual address within the paged text region into a pointer to
* the corresponding page table entry.
*
* Input Parameters:
* vaddr - The virtual address within the paged text region.
*
* Returned Value:
* A pointer to the corresponding page table entry.
*
* Assumptions:
* - This function is called from the normal tasking context (but with
* interrupts disabled). The implementation must take whatever actions
* are necessary to assure that the operation is safe within this
* context.
*
****************************************************************************/
uint32_t *arm_va2pte(uintptr_t vaddr)
{
uint32_t L1;
uint32_t *L2;
unsigned int ndx;
/* The virtual address is expected to lie in the paged text region */
DEBUGASSERT(vaddr >= PG_PAGED_VBASE && vaddr < PG_PAGED_VEND);
/* Get the L1 table entry associated with this virtual address */
L1 = *(uint32_t*)PG_POOL_VA2L1VADDR(vaddr);
/* Get the address of the L2 page table from the L1 entry */
L2 = (uint32_t*)PG_POOL_L12VPTABLE(L1);
/* Get the index into the L2 page table. Each L1 entry maps
* 256 x 4Kb or 1024 x 1Kb pages.
*/
ndx = (vaddr & 0x000fffff) >> PAGESHIFT;
/* Return true if this virtual address is mapped. */
return &L2[ndx];
}
#endif /* CONFIG_PAGING */
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